In palettisation systems like other packing and packaging areas, it is more and more important to restrict the amount of packaging material used for cost and environmental reasons, or at least use recyclable materials and systems. For these reasons, and due to the reduction of packaging material, the packages become flexible, or at least partially flexible. When such flexible or semi-flexible packages are grouped and stacked into a pallet, issues arise concerning the pallet stability, especially during handling and transportation, that is to say when the pallet is moved and is subject to external mechanical forces and constraints. In order to enhance the overall mechanical resistance of the pallet constituted of flexible or semi-flexible packages, the headspace of such packages is generally filled with gas, which can be air, or more generally a neutral gas such as nitrogen (N2). Such a gas is filled at a higher pressure than the atmospheric pressure, so that the flexibility of the package is reduced or cancelled. Filling the headspace however requires an additional equipment in the manufacturing lines, which adds complexity and costs to the process, and is therefore clearly disadvantageous.
In the palettisation systems, it is however important to improve the stability of the pallets so that, while the size of a pallet is kept unchanged and the amount of packaging material that is used is decreased, the overall mechanical properties of the pallet are improved. If possible, it is crucial for a constant volume of the pallet, to increase the volume of individual packages constitutive of the said pallet.
Different systems have been developed which involve stretching films for wrapping the pallet once it is constituted, or similar systems. However, such over wrapping film solutions require a specific equipment to wrap the pallet with film, and also require quite a large amount of packaging material, or even several materials.
Moreover, it was found that during transportation or handling of the pallets, a high pressure is applied onto the pallet which is directed in the transversal direction. It is therefore a major issue to also reinforce the pallets to lateral/transversal forces, on top of the high top load resistance a pallet must have.
U.S. Pat. No. 4,805,793 granted to Brandt et Al. and published Feb. 21, 1989, discloses a stackable bottle which comprises a recess in its bottom portion, such that when two bottles are stacked one above the other, the neck and top handle if any of the lower bottle, fit into the recess of the upper bottle, so as to maximize volume filling on the pallet. Such a configuration also allows to increase the top load resistance of the pallet, because vertical forces applied to each bottle in the pallet stand on a larger surface, i.e. on the shoulders of said bottle, instead of standing on the closure and neck of the same. The bottles disclosed in this document are however reinforced, for example with ribs and grooves in their walls, and the latter comprise a high thickness along with the high top load resistance requirement. Such bottles, while allowing a good resistance in one direction of the pallet (vertical), still do not show sufficient resistance to mechanical constraints applied in other directions to the pallet. What is more, such bottles do not solve at all the problem of saving packaging material for ecological and economical reasons, while keeping same or even improving their overall mechanical resistance.
WO 2007/112598 A1 is an international patent application to Dean Lane, published Oct. 11, 2007. It discloses a stackable ribbed bottle system, similar to the packaging system disclosed in U.S. Pat. No. 4,805,793. Similarly, WO '598 packages do not show sufficient resistance to mechanical constraints applied to the pallet in other directions than vertical. Also similarly to the drawbacks in US '793, the bottles disclosed in WO '598 do not solve at all the problem of saving packaging material for ecological and economical reasons, while keeping same or even improving their overall mechanical resistance.
It is therefore a main purpose of the present invention to provide stackable bottles that participate to improving the overall pallet stability when palletized, and especially the top lad and transversal load resistance, while being economic to produce and easy to handle, stack and transport.
Finally, it is a further objective of the present invention to provide flexible stackable packages which are structured so that they can be stacked in various position, depending on whether they need to be stacked, stored, transported, or during dispensing.